Janux Therapeutics announces discontinuation of JANX008 clinical development

Janux Therapeutics (JANX) announced that it will discontinue further clinical development of JANX008, its EGFR-targeted Tumor Activated T Cell Engager program. Following completion of the Phase 1a portion of the study, which included dose escalation and expansion cohorts across multiple solid tumor indications, and an internal review of the data, the Company has determined to prioritize development resources toward other pipeline opportunities. The decision to discontinue JANX008 is program-specific and does not impact the Company’s broader TRACTr platform strategy. As part of its disciplined portfolio prioritization process, the Company evaluated the JANX008 dataset against predefined development criteria. While durable responses were observed in select patients through extended follow-up, the overall magnitude and consistency of activity were not sufficient to support continued development relative to other pipeline programs. The study also generated insights relevant to the broader TRACTr platform. The occurrence of cytokine release syndrome (CRS) was infrequent and primarily limited to Grade 1, enabling Safety Review Committee approval for outpatient dosing. In addition, JANX008 demonstrated a differentiated tolerability profile relative to conventional EGFR-targeted therapies, with minimal gastrointestinal, dermatologic, and subcutaneous adverse events typically associated with EGFR antibodies and tyrosine kinase inhibitors. These findings, together with the ability to dose beyond the limitations of conventional T cell engagers, support the potential of the TRACTr platform to improve safety. While musculoskeletal adverse events were dose-limiting, reflecting constraints associated with the EGFR target, the TRACTr format enabled a sufficient therapeutic window to assess clinical activity across a range of doses.